Crimping tool



March 23, 1965 w. R. OVER 3,174,323

CRIMPING TOOL Filed Oct. 5. 1961 3 Sheets-Sheet l March 23, 1965 w. R.OVER CRIMPING TOOL 3 Sheets-Sheet 2 Filed 061;. 5. 1961 March 23, 1965W. R. OVER CRIMPING TOOL Filed Oct. 5. 1961 3 Sheets-Sheet 3 UnitedStates Patent 3,174,323 CRIWHNG TQDL William R. fiver, Union Deposit,Ea, assignor to AMP Incorporated, Harrisburg, Pa. Filed Oct. 5, 1961,Ser. No. 143,151 tClaims. (Cl. 72-412) This invention relates to poweractuated tools for crimping loose-piece electrical connectors ontoWires.

Many types of electrical connectors are supplied in loose-piece form,that is the connectors are separated from each other rather than beingin the form of a strip or belt. When a loose-piece connector is crimpedonto a .wire by means of a hand tool, the operator is faced with theproblem of manipulating the tool, the wire and the connector during thecrimping operation. Since the operator can hold only two of these itemsat one time, it is common practice to first insert the wire into theuncrimped connector and then, with one hand, position this uncrimpedconnector-wire combination between the dies of the tool which is held inthe operators other hand. This procedure is not entirely satisfactoryfor the reason that when the connector is loosely supported on the wireprior to crimping, extreme care must be exercised to ensure that the endof the wire will remain properly located with respect to the connectoruntil the crimping operation is carried out. Furthermore, when theoperator follows this procedure he must precisely position the connectorbetween the crimping dies notwithstanding the fact that he does not havedirect manual control over the connector during this interval butcontrols its location only by moving the wire on which it rests.

Some manually held crimping tools incorporate devices for locating andholding the connector on the tool with respect to the dies so that theoperator can take the tool in one hand and position the connector in thetool with the other hand in the connector holder. He then has one handfree to grasp the wire and insert it into the uncrimped connector andhold the wire in its proper position while he actuates the tool. Theseconnector holding and locating devices cannot, however, be provided onall types of manually held crimping tools, and are frequentlyimpractical because of the fact that they are not universal, i.e. theycannot be used with different types of connectors.

It is an object of the present invention to provide an improved powerassisted crimping tool for crimping loosepiece connectors. A furtherobject is to provide a power assisted crimping tool having meansfor'holding and loeating [an uncrimped connector on the tool thereby topermit the tool operator to use one hand for holding the tool and theother hand for inserting the wire into the uncrimped connector. A stillfurther object is to provide a power assisted crimping tool having areciprocable ram with a manually operated take-up device for the ram. Astill further object is to provide a connector holding and locatingmeans which grips the ferrule portion of the connector rather than thetongue or other functional end of the connector.

These and other objects of the invention are achieved in a toolcomprising a cylindrical housing having a reciprocable ram therein. Anormally broken toggle in the housing has one end pivotally connected tothe ram and the other end pivoted to a stationary pivot pin .so

that upon straightening of the toggle the ram is moved from aninitialretracted position to:an extended position. A camming block has asurface engageable withthe knee joint of the toggle tostraighten thetoggle and (to impart the workingor crimping stroke ,to the ram. Thetoggle and ram are not directly connected :to the cam ,so that the ramcan be moved in the direction of its working 3,174,323 Patented Mar. 23,1965 stroke independently of the cam. This independent motion of the ramis imparted thereto by means of a slidable finger piece on the toolhousing and constitutes the quick take-up arrangement by means of whichthe movable die on the ram is moved towards the fixed die. In use, theram is initially moved by this separate finger piece until an uncrimpedterminal positioned between the crimping dies is gripped between thedies and the cam is thereafter actuated to impart the final increment ofmovement to the ram to crimp the terminal. It then becomes necessary toreturn the ram to its initial position for the next operating cycle ofthe tool. This is accomplished by me ans of a ram return meanscomprising a plate which has a flange or shoulder engageable with theram after it has completed its working stroke to crimp the terminal.This plate is resiliently biased in the direction opposed to thedirection of the working stroke of the ram and is moved in the directionof the working stroke by the cam itself. The arrangement is such thatwhen the resiliently biased plate is moved by the cam, it engages theram and during the return stroke returns the ram to its initialposition. At the end of the return stroke, the plate is automaticallydisengaged from the ram thereby releasing it for movement through thefinger piece during the next operating stroke of the tool. In thedrawing:

FIGURE lis a perspective view of a tool in accordance with theinvention.

FIGURE 2 is a central longitudinal sectional view of the tool of FIGURE1 showing the positions of the parts at the beginning of the operatingcycle.

FIGURE 3 is a view similar to FIGURE 2 but showing the positions of theparts after the manually actuated quick take-up device has been operatedto move the ram upwardly for a portion of the stroke.

FIGURE 4 is a fragmentary side vview similar to FIG- URE 2 but showingthe return plate and the latch plate by means of which the ram isretracted.

FIGURES 5 and 6 are views similar to FIGURE 4 but showing the relativepositions of the parts at successive stages of the operating cycle.

FIGURE 7 is a view taken along the lines 7--7 of FIGURE 6.

FIGURE 8 is a perspective view of a return plate which forms part of theinvention.

FIGURE 9 is a perspective view of a latch plate which cooperates withthe return plate to effect retraction of the ram; and

FIGURE 10 is a perspective view of a terminal of a type adapted to becrimp'ed by the tool of FIGURE 1.

The embodiment of the invention disclosed herein is provided on .a poweractuated manually held crimping tool of the general type disclosed andclaimed in thecopending application of Martin L. .Klingler, Serial No.36,023, filed June 14, 19.60 for Compressing Tool, which became PatentNumber 3,053,112. Tools of this type oversized opening 8 is provided inthe cylinderhead .6

and a ram formed .in two threaded together extensible parts 19, .12,eXtends through this opening. The exter- :nal surface of head ,6 has apair of .upstandingears 14- which receive the lower arm 18 of agenerally C-shaped frame 16. The lower arm .18 has an opening thereinwhich conforms to the cross sectional shape of the ram and guides theram along a rectilinear path to move the a crimping dies relativelytowards and away from each other. The movable crimping dies 28 aremounted on the ram 12 by means of a die holder 24 and the fixed crimpingdies 30 are mounted on the upper arm 20 of frame 16 by means of a dieholder 26. Dies of the type shown are adapted to crimp the cylindricalferrule portion 32 of a terminal onto the end 36 of a wire 38. Thisconnector has a functional erid which comprises a ring tonque 34 in thedisclosed embodiment but which may take any one of a variety ofalternative forms.

The lower end 10 of the ram is pivotally connected to a togglecomprising a pair of links 40, 42 having their ends commonly connectedon a pivot pin 44. The links 40, 42 each comprise two parallel side barsintegrally joined at their ends. The two links have their common endsfitting within each other at the common pivotal axis 44. A cam followeror roller 46 surrounds pivot pin 44 for cooperation with a camming blockas described below. The lower end of the toggle linkage, that is thelower end of the link 40, is pivotally mounted on a pin 48 which ismounted in the sidewalls of the cylinder head extension. The upper endof the link 42 is pivotally connected at 50 to the lower end of the ramsection 10. It will be apparent that when the toggle is broken the ramis in its retracted position and that when the toggle is straightenedthe ram is in its extended position. Straightening of the toggle thusimparts the working stroke to the ram during which the connector iscrimped.

A block 52 is disposed between the opposed sidewalls 5 of the cylinderhead extension and has an arcuate camming surface 54 on its side whichfaces the pivot pin 44. Upon relative upward movement of this block, thetoggle is straightened by the face 53 of the cam and then by the camsurface 54 thereby to impart the crimping force or thrust to the ram.The lower end of block 52 is centrally slotted at 56 and a link 58extends into this slot and is pivoted thereto at 59. This link extendsthrough an oversized opening in a separator plate 62 and is pivoted atits opposite end to a piston 60 contained within the lower part of thehousing 2. The piston is normally biased downwardly toward the lower endof the housing by means of a spring 66 which is interposed between plate62 and the recess in the piston 60. The separator plate 62 referred toabove bears against the lower end of'the cylinder head extension 5, 7and is maintained in position by the force of the spring 66.

Movement of the block 52 is controlled by two pairs of links 68, 70mounted on each side of the block and externally of the sidewalls 5 onthe cylinder head exten sion. The links 68 are pivotally connected atone end to the pin 48 on which the lower end of the toggle is pivotallymounted. Links 63 are pivotally connected to the block-52 by means of apin 72 which extends through the block and through the recess or slot56. The links 70 are pivotally mounted on fixed pins 76 in the opposedsidewalls 5. It will be noted that the pins 76 do not extend through thecylinder head extension since this space between sidewalls 5 must beleft unobstructed for the movement of the ram toggle 40, 42. Theopposite ends of the links 70 are pivotally connected to a pivot pin 74which extends through the upper end of the block 52. It will be apparentfrom the foregoing that upon upward movement of the piston 60, the block52 travels along an arcuate path from the position of FIGURE 3 and thecam surface 54 is brought into engagement with the cam follower 46 toimpart the crimping force to the rann Advantageously, a rack bar 78 isheld against the lefthand side of block 52 as viewed in the FIGURES 4-6by means of a plate 80 secured to this side of the block. The rack barhas teeth intermediate its ends for engagement with a pawl 82 pivoted onpin 72 in slot 56 of the block. This pawl is biased downwardly as viewedin the drawing in a counterclockwise direction by means of a spring 84and the end of the pawl is so shaped as to permit it to be reversed withrespect to the teeth on the rack bar in either of two depresisons 86, 88in the bar on each side of the teeth. The arrangement is such that aftermovement of the block along its arcuate path has commenced during acrimping stroke, the direction of movement of the parts can not bereversed until the stroke has been completed thereby preventing partialcrimping of a connector as is explained in the aboveidentified KlinglerPatent Number 3,053,112.. It is desirable to provide a leaf spring 90 inthe cylinder head extension with an end bearing against the link 40 sothat the toggle 40, 42 will be partially broken by this spring duringthe return stroke of the tool when the cam follower has been freed frompressure.

It will be apparent from the foregoing description that the block 52 andthe toggle for the ram 10, 12 are not directly connected to each otherand that final straightening of the toggle is accomplished only by thecam surface 54. Means are provided for substantially, but not fully,straightening this toggle and driving the ram upward through asubstantial portion of its stroke to grip the terminal barrel 32 betweenthe crimping dies. This means comprises a finger piece 92 slidablymounted in a guide slot 96 on the surface of housing 2. This fingerpiece extends through aligned slots 94 in the housing and the cylinderhead extension wall 7 and is secured to the lower end of ram 10 by meansof a fastener 93. When the tool is held in the hand, this finger piececan be pushed upwardly by the thumb of the operator to drive the ramupwardly through a portion of the cycle until the ferrule portion of theterminal is gripped between the dies. Thereafter, the end of the wire ispositioned in the terminal, the air supply system is actuated by trigger9 and compressed air is admitted into the lower endof the housing 2 todrive the piston 60 upwardly. As the block 52 moves along its arcuatepath, the cam surface 54 straightens the toggle linkage on the ram andimparts the crimping force to the dies.

When the compressed air is exhausted from the lower end of the housing,the pistonand block 52 move relatively downwardly under the influence ofspring 66. The ram is automatically returned to its retracted positionby means of a pair of plates 98 having generally parallel sides 100, 102and having an ear 104 struck out from their upper ends as viewed in thedrawing. A triangular notch 106 is provided at the opposite ends of theplate and a toe 108 extends from one side of. this opposite end while anextension 110 projects fromthe other end adjacent to the ear 104. A camsurface 112 extends obliquely from the side of extension 110 to surface100. These plates are positioned against the outside surfaces of thelinks 68 and 70 with the ears at the upper end of the toolfacingoutwardly from the sidewalls. Latch plates 114 are pivotally mounted oneach side of these plates on the pivot pin 50, these latch plates havingelongated slots 116 therein to permit movement relative to the fixedpivot pins 48, 76. A shoulder 117 is provided in each latch plateadjacent to the pin 50- for engagement with the ears 104 of the returnplates 98 in a manner described below.

The return plates are held in position by means of springs 118 which aresecured at one end .to brackets 120 on separator plate 62 and at theiropposite ends 122 to the ears 104. The apices of the notches 106 areadapted to be engaged by pins 124 which are provided on the links Inuse, parts will normally be in the position of FIG- URES 2 and 4 withtheram in-its retracted position. The operator first holds or positionsthe ferrule portion 32 of the terminal againstthe fixed die 30 and movesthe finger piece upwardly until the ferrule of the terminal is grippedbetween the dies 28,: 30 as shown in FIGURE 1. FIGURES 3 and 5 show therelative positions of the parts within the housing 2 after this upwardmovement of the finger piece by the operator. The operator can thenrelease his grip upon the terminal 32.

and grasp the wire 38 in his other hand and position its stripped end 36in the ferrule of the terminal. The operator then actuates the airsupply system by depressing trigger 9 to drive the block 52 along itsarcuate path and impart the final increment of motion to the ram for itsworking stroke thereby to crimp the terminal. During this working strokeof the ram, the plates 98 are pushed relatively upwardly bythe drivepins 124 until the projecting ears reach the shoulders 117. The platesthen move laterally until these areas abut the shoulders on each of thelatch plates 114 as shown in FIGURE 6. The motion of the plates 98during this portion of the cycle is partially controlled by the spring118. The brackets 120 to which the lower ends of these springs aresecured are not centrally located on the separator plate 62 but areslightly displaced from the center plane of the tool. The plates arethus biased relatively towards the latch plates 114 and as soon as theears 104 encounter the shoulder 117, the plates are moved laterallyuntil these ears abut the shoulders. This lateral movement of the plates93 is thus brought about by a limited clockwise swinging of the plates(as viewed in FIGURES 5 and 6) about the pins 124- which serve aspivotal axes.

After completion of the crimping operation, the lower end of thecylinder is exhausted and the piston 60 returns to its retractedposition under the influence of the spring 66. Upon retraction of thepiston 6% the camming block 52 is also retracted and returned to itsoriginal position and the pins 124 move downwardly from the position ofFIGURE 6 to the position of FIGURE 4. When the pins 124 move downwardlyand away from the plates 98, these plates are free to move downwardlyunder the influence of the springs 118 and the interengagement of theears 104 of plates 98 and shoulders 117 of the latch plates 114 causesthe plates 98 to pull the latch plates 114 downwardly from the positionof FIGURE 6 to the position of FIGURE 4. The ram 12 is also moveddownwardly since it is connected to the plates 114 by the pin 50. Duringthe final portion of the downward movement of plates 93 and 114, thecamming surfaces 112 of the plates 98 move against the pins 76 causingthe plates 93 to swing counterclockwise about their lower ends. Thisswinging motion of the plates 98 brings about the disengagement of theears 104 from the shoulders 117 of the latch plates so that the plates98 can'return to their initial position (FIGURE 4) with the pins 124seated in the apices of the notches 1%. It will be under stood that thefinger piece 92 is pulled downwardly with the ram during this returnstroke.

I claim:

1. In a compressing tool comprising, a housing, a cam in said housing,said cam being pivotally secured to one end of a link means, said linkmeans being pivotally secured to said housing at its opposite end, meansfor moving said cam along an arcuate path defined by said link means, atoggle mechanism in said housing having one end pivotally mounted on afixed axis and having a knee joint in engagement with said cam, a ram,the other end of said toggle being pivotally secured to said ramwhereby, upon movement of said cam, said toggle is straightened out andsaid ram is moved, the improvement comprising: a finger piece for movingsaid ram and strightening said toggle independently of said cam therebyto provide a quick take-up for said ram, and ram return means acting onsaid ram independently of said cam to return said ram after crimping,said ra-m return means comprising a plate resiliently biased in thedirection of return movement of said ram, said plate having means forengagement with said link means during movement of said cam in thedirection of movement of the Working stroke of said ram, and said platehaving hook means for engagement with said ram after the conclusion ofmovement of said plate in the direction of movement of the workingstroke of said ram.

2. In a compressing tool comprising, a housing, a cam in said housing,said cam being pivotally secured to one end of a link means, said linkmeans being pivotally secured to said housing at its opposite end, meansfor moving said cam along an arcuate path defined by said link means, atoggle mechanism in said housing having one end pivotally mounted on afixed axis and having a knee joint in engagement with said cam, a ram,the other end of said toggle being pivotally secured to said ramwhereby, upon movement of said cam, said toggle is straightened out andsaid ram is moved in a working stroke, the improvement comprising: afinger piece for moving said ram and straightening said toggleindependently of said cam thereby to provide a quick take-up for saidram during said working stroke, and resiliently biased ram return meansengageable with said ram after completion of said working stroke toreturn said ram to its initial position independently of said cam, saidresiliently biased ram return means being disengageable from said ramafter said return stroke to permit use of said finger piece withoutrestraint by said ram returns means in the next working stroke.

3. In a compressing tool comprising, a housing, a ram in said housing, anormally broken toggle having one end pivotally connected to said ramwhereby, upon straightening of said toggle said ram is moved from aninitial retracted to an extended position, cam means engageable withsaid toggle to straighten said toggle and impart said working stroke tosaid ram, the improvement comprising: a slidable finger piece for movingsaid ram independently of said cam thereby to provide a quick take-upfor said working stroke of said ram, and ram return means engageablewith said ram at the end of said working stroke to return said ram tosaid initial position, said ram return means being resiliently biased inthe direction of the return stroke of said ram and being disengageablefrom said ram at the end of said return stroke thereby to permitmovement of said ram by said finger piece without restraint by said ramreturn means during the next operating cycle of said tool.

4. A compressing tool for electrical connectors comprising, a housing, aram in said housing movable, during a working stroke, from a retractedposition to an extended position and, during a return stroke, to saidretracted position, a movable crimping die on said ram, a fixed crimpingdie cooperable with said movable die to crimp an electrical connector, afinger piece slidable along said housing in the direction of movement ofsaid ram, said finger piece being connected with said ram whereby, uponmovement of said finger piece, said ram is moved thereby to provide aquick take-up of a substantial portion of said working stroke of saidram, power means in said housing acting on said ram for moving said ramthrough the terminal portion of said working stroke, and resilientlybiased ram return means for returning said rain to said initialposition, said ram return means being automatically engageable with saidram upon completion of said working stroke and being automaticallydisengageable from said ram upon completion of said return strokewhereby said ram is free to be moved by said finger piece withoutrestraint by said ram return means during the next operating cycle ofsaid tool.

5. In a compressing tool comprising a housing, a cam in said housing,said cam being pivotally secured to one end of a link means, said linkmeans being pivotally secured to said housing at its opposite end, meansfor moving said cam along an arcuate path defined by'said link means, atoggle mechanism in said housing having one end pivotally mounted on afixed axis and having a knee joint in engagement with said cam, a ram,the other end of said toggle being pivotflly secured to said ramwhereby, upon movement of said cam, said toggle is straightened out andsaid ram is moved, the improvement comprising: a plate disposed besidesaid cam, resilient means normally biasing said plate in a directionopposite to the direction of movement of said ram when said toggle isstraight- 7 ened, means acting between said link means in said plate formoving said plate in the direction of movement of said link means duringstraightening of said toggle, latch means on the leading end of saidplate engageable with said ram at the conclusion of arcuate movement ofsaid link means and after said toggle has been straightened whereby saidtoggle is broken and said ram is retracted under the influence of saidresilient means, said latch means being automatically disengageable fromsaid ram after return of said ram to its initial position and afterbreaking of said toggle, and a finger piece for moving said ReferencesCited in the file of this patent UNITED STATES PATENTS 2,467,020 FischerApr. 12, 1949 2,887,916 Freedom May 26, 1959 3,053,112 Klingler Sept.11, 1962

1. IN A COMPRESSING TOOL COMPRISING, A HOUSING, A CAM IN SAID HOUSING,SAID CAM BEING PIVOTALLY SECURED TO ONE END OF A LINK MEANS, SAID LINKMEANS BEING PIVOTALLY SECURED TO SAID HOUSING AT ITS OPPOSITE END, MEANSFOR MOVING SAID CAM ALONG AN ARCUATE PATH DEFINED BY SAID LINK MEANS, ATOGGLE MECHANISM IN SAID HOUSING HAVING ONE END PIVOTALLY MOUNTED ON AFIXED AXIS AND HAVING A KNEE JOINT IN ENGAGEMENT WITH SAID CAM, A RAM,THE OTHER END OF SAID TOGGLE BEING PIVOTALLY SECURED TO SAID RAMWHEREBY, UPON MOVEMENT OF SAID CAM, SAID TOGGLE IS STRAIGHTENED OUT ANDSAID RAM IS MOVED, THE IMPROVEMENT COMPRISING: A FINGER PIECE FOR MOVINGSAID RAM AND STRIGHTENING SAID TOGGLE INDEPENDENTLY OF SAID CAM THEREBYTO PROVIDE A QUICK TAKE-UP FOR SAID RAM, AND RAM RETURN MEANS ACTING ONSAID RAM INDEPENDENTLY OF SAID CAM TO RETURN SAID RAM AFTER CRIMPING,SAID RAM RETURN MEANS COMPRISING A PLATE RESILIENTLY BIASED IN THEDIRECTION OF RETURN MOVEMENT OF SAID RAM, SAID PLATE HAVING MEANS FORENGAGEMENT WITH SAID LINK MEANS DURING MOVEMENT OF SAID CAM IN THEDIRECTION OF MOVEMENT OF THE WORKING STROKE OF SAID RAM, AND SAID PLATEHAVING HOOK MEANS FOR ENGAGEMENT WITH SAID RAM AFTER THE CONCLUSION OFMOVEMENT OF SAID PLATE IN THE DIRECTION OF MOVEMENT OF THE WORKINGSTROKE OF SAID RAM.